Electronic fuses may commonly be found in many integrated circuit designs. One exemplary electronic fuse is a poly silicon fuse link that is coupled to a voltage line (usually referred to as FSource) at one end, and to an n-channel field-effect transistor (NFET), which is usually referred to as a programming FET, at its opposite end. During a fuse programming operation, a voltage is supplied by the FSource and the programming FET is turned on for a certain duration of time, which allows controlled electromigration to occur. The controlled electromigration causes a salicide/boron pile-up on an anode side of the poly fuse link. As a result, the resistance across the poly fuse link may rise from hundreds of ohms to many Kilo-ohms, in effect opening or “programming” the electronic fuse.
As is known in the art, the rise in fuse resistance during a fuse programming operation must meet a particular integrated circuit chip characteristic requirement. Using a “one size fits all” approach to a fuse programming operation may have two undesirable results: (1) a ruptured fuse or (2) a weakly programmed fuse. As such, if chip characteristics vary, the fuse programming process may need to be altered in order to provide the desired fuse yield. That is, the environmental variables of a fuse programming process, e.g., programming Vdd, FSource voltage, or the fuse programming duration, may need to be varied on a chip-by-chip basis according to a different characteristic requirement of each chip. Integrated circuit chip manufacturers have satisfactorily determined on a chip-by-chip basis whether and how one or more environmental variables need to be altered. As a result, the proper fuse programming conditions may be applied by automated test equipment during the normal manufacturing test flow and, thus, the electronic fuse programming operation is successfully performed.
While the conditions and parameters that are related to the electronic fuse programming process, which includes the environmental variables of a fuse programming process, are known to integrated circuit chip manufacturers, they are not known to customers that are receiving the chip, as it is not the manufacturer's practice to supply this information to customers. However, customers may wish to program electronic fuses in the field for a wide variety of reasons and, thus, customers may benefit from knowledge of the electronic fuse programming process. For example, upon receiving a chip of the customer's specifications from the manufacturer, a customer may wish to program electronic fuses in order to implement functional or performance settings therein. Unfortunately, without the proper electronic fuse programming information that takes into account the environmental variables of the customer's chip specifically, programming electronic fuses in the field (i.e., outside the manufacturing test environment) will likely result in low fuse yield.
Integrated circuit chip manufacturers have utilized an electronic chip identification (ECID) macro of a chip which may be used for storing non-test related data (e.g., chip identification data, such as lot number, wafer ID, chip coordinates). Chip customers may access this chip identification information. However, integrated circuit chip manufacturers have not provided customers in any fashion the knowledge to extend manufacturing processes (e.g., effectively program electronic fuses) to the field.
A need exists for a method of providing optimal field programming of electronic fuses, in order to enable chip customers to perform an electronic fuse programming process in the field that produces a desired fuse yield.